They were not prepared for what happened Friday evening, when police say Trotter stabbed her own 4-year-old son to death.

"I never would have thought in a trillion years that this would happen," her brother, LeRonn Trotter, 44, said Saturday.

Police continued to investigate what led the 40-year-old woman to commit such a violent act against her own small child, Joseph "Turtle" Artis.

But even Joseph's grandmother, who had custody of him, doubts answers will come.

Carolyn Trotter, 64, and other family members said Trotter had a history of mental illness. She has been diagnosed with bipolar disorder, manic depression and schizophrenia, they said. She had spent years in a facility for behavioral and mental health treatment. They said the center kicked her out when she became pregnant with Joseph.

It was around this time she stopped taking her medication and she began to loose her grip on reality. LeRonn noticed it one day when he saw her scribbling designs in markers across her legs.

On Friday, Tasha Trotter was visiting Joseph in the 13th Avenue S home where he lived with his grandmother about 6 p.m. Without warning, police said, she grabbed a kitchen knife, rushed into a room where the child had gone and stabbed him repeatedly. Neighbors heard screams from near Carolyn Trotter's home. They saw Tasha Trotter lay her bleeding son on the ground.

Joseph was taken to Bayfront Health St. Petersburg, where he died less than an hour later.

On Saturday, police said Trotter still had not told them what prompted her actions.

Joseph's aunt, Gwendolyn Rose, said she saw the two together about a year ago. Back then, she said, all seemed well. "He loved his mom," she said. "The mom had him and she took care of him."

Rose lives in Naples and has had custody of Joseph's 3-year-old sister, Kristian, since she was 7 months old, she said.

Despite Tasha Trotter eccentricities, her relatives said she appeared to love her son and enjoyed indulging him. If Joseph wanted to watch TV for hours, she would let him. Any kind of food he felt like, she got it for him.

Court records show Joseph's life, though short, was turbulent.

In 2009, when he was less than 4 months old, Trotter filed a domestic violence injunction against his father, Joseph Artis III. She was granted temporary custody of the child and the father was allowed only supervised weekly time-sharing visits at a domestic violence shelter.

According to the Department of Children and Families, Trotter agreed to give her mother temporary custody of Joseph in 2010. The following year, Tasha Trotter lost custody permanently. She was allowed only supervised visits, with her mother always present.

Joseph's case was closed and DCF contact stopped in December of 2011, a spokesman said.

Trotter moved in and out of halfway houses and assisted care facilities, police said.

She was charged with first-degree murder and booked into the Pinellas County Jail. A judge denied her bail.

Her family spent a rainy Saturday with relatives, not wanting to return to the scene of the stabbing. They said they fear the gruesome flashbacks they might encounter. They said they were not looking for answers, knowing none would come. But they hoped the incident would start a conversation about mental health care.

"We have to seriously address the issue," Carolyn Trotter said.

Times researcher Natalie Watson contributed to this report. Weston Phippen can be reached at wphippen@tampabay.com or (727) 893-8321.